1. Field of the Invention
The present invention relates to a printing device enabling both simplex printing and duplex printing on a print medium, and to a control method for the printing device.
2. Description of Related Art
Printing devices (simply “printers” below) that can print on both sides of paper or other print medium (commonly called “duplex printing”) are taught in Japanese Unexamined Patent Appl. Pub. JP-A-03-027434 and Japanese Unexamined Patent Appl. Pub. JP-A-04-001067.
Japanese Unexamined Patent Appl. Pub. JP-A-03-027434 and Japanese Unexamined Patent Appl. Pub. JP-A-04-001067 teach a printing system that has a repagination unit, an odd-page processing unit, an even-page processing unit, and a reverse-side print processing unit. The repagination unit repaginates and updates the page numbers when a duplex printing command is issued by the host computer. The odd/even page determination unit determines whether a page number is odd or even. If the page number is odd, the odd-page processing unit prints on the front of a sheet and then discharges the sheet into an intermediate holding tray. If the page number is even, the even-page processing unit writes the start address and length of the even page print command string to a control table. The reverse-side print processing unit prints the even pages on the second side of the sheets on which the odd pages have been printed on the first side and are stored in the holding tray.
The host computer issues a duplex printing command to the printing system in order to print on both sides. If the storage capacity of the holding tray is exceeded or the end of the document is detected during the first-side printing process, operation switches from the first-side printing process to the second-side printing process. More specifically, a command must be asserted by the host computer to switch from single-sided printing (known as “simplex printing”) to duplex printing.
Printers that switch between duplex printing and simplex printing according to the on or off state of a DIP switch are also known from the literature.
In order to switch printing from simplex printing to duplex printing or from duplex printing to simplex printing with the methods described above, the user must change the setting before each printing process starts.
When printing sales receipts on continuous paper, for example, the length of each receipt differs with each transaction. The issued receipt is long when a large number of products are purchased, and is short when few products are purchased. The method of the related art requires the operator to change the setting each time printing switches between duplex printing and simplex printing, and this is annoying. It is also particularly a problem when printing receipts, an operation which typically requires quick processing.
Furthermore, because the print data differs in each receipt printing process (each print job), the balance between the results of printing on front and back changes according to the location of the break between the first-side data and the second-side data in the print data contained in each print job.
Yet further, when the details of the purchased products are printed on the front and coupons are printed on the back, printing on the back may start from the middle of a printed image unless a break is inserted between the text data and the image data. If printing the back starts in the middle of the image data, receipts that have a positive visual impact on the customer cannot be issued. It is therefore desirable to be able to freely insert a break between the first-side data and the second-side data in each print job.
In order to print receipts that have a greater visual impact on the customer, receipts are not often printed with text data combined with a logo, and it is often desirable to insert logos in duplex printing jobs. Inserting a logo enables the merchant to appeal to the user, and produces receipts that are easier to read.